<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>水平线</title>
</head>
<body>
<hr>
<hr color="red">
<hr color="green" width="300px">
<hr color="blue" width="50%">
<hr color="yellow" size="10">
<hr color="red" size="20" width="50%" align="left">
<hr color="green" size="20" width="50%" align="center">
<hr color="blue" size="20" width="50%" align="right">
</body>
</html>